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Some bacteria are symbiotic in tumor tissues, and metabolites of several bacterial species have been found to cause DNA damage. However, to date, the association between bacteria and host genetic alterations in colorectal cancer (CRC) has not been fully investigated. We evaluated the association between the intra-tumor microbiome and host genetic alterations in 29 Japanese CRC patients. The tumor and non-tumor tissues were extracted from the patients, and 16S rRNA genes were sequenced for each sample. We identified enriched bacteria in tumor and non-tumor tissues. Some bacteria, such as Fusobacterium, which is already known to be enriched in CRC, were found to be enriched in tumor tissues. Interestingly, Bacteroides, which is also known to be enriched in CRC, was enriched in non-tumor tissues. Furthermore, it was shown that certain bacteria that often coexist within tumor tissue were enriched in the presence of a mutated gene or signal pathway with mutated genes in the host cells. Fusobacterium was associated with many mutated genes, as well as cell cycle-related pathways including mutated genes. In addition, the patients with a high abundance of Campylobacter were suggested to be associated with mutational signature 3 indicating failure of double-strand DNA break repairs. These results suggest that CRC development may be partly caused by DNA damage caused by substances released by bacterial infection. Taken together, the identification of distinct gut microbiome patterns and their host specific genetic alterations might facilitate targeted interventions, such as modulation of the microbiome in addition to anticancer agents or immunotherapy.

Abstract Biliary tract cancer (BTC) is clinically and pathologically heterogeneous and responds inadequately to treatment. A small section of patients develop resectable disease, although the relapse rates are high; the benefits of adjuvant capecitabine chemotherapy for BTC are now understood, and gemcitabine‐based combination chemotherapy is the first line of therapeutic strategy for BTC; however, alternative therapy for BTC is not known. Genomic profiling can provide detailed information regarding the carcinogenesis, identification, and therapy for BTC. Currently, confirmed restorative targets for BTC are lacking. In this review, we aimed to analyze the preclinical and clinical implications of a spectrum of genomic alterations associated with new potentially remedial targets. We focused on eight draggable genes for BTC, which were described as having evidence of therapeutic impact (evidence level 2A‐3B) based on the clinical practice guidance for next‐generation sequencing in cancer diagnosis and treatment; these include ERBB2, NTRK1, RNF43, CDK6, CDKN2B, FGFR2, IDH1, and IDH2. Moreover, some of the BTC present microsatellite instability, hypermutation, and germline variants, which we also reviewed. Finally, we discussed the therapeutic options based on the next‐generation sequencing findings in BTC. Studies have demonstrated that BTC includes subgroups with individually distinct driver mutations, most of which will be targeted with new treatment plans.

Abstract Nearly 50% of primary lung carcinoma patients present with distant metastasis at their first visit. However, gastrointestinal tract (GIT) metastasis is an infrequent impediment. Herein, we report a case of progressive dysphagia and epigastralgia as an initial manifestation of recurrence as gastric metastasis of primary lung squamous cell carcinoma (SCC) after curative surgery. A 64‐year‐old man was diagnosed with primary lung SCC of the right lower lobe, and underwent thoracoscopic lower lobectomy. One year after lobectomy, computed tomography (CT) scan showed a gastric fundal mass located in the gastric cardia which measured 5 cm. Endoscopic biopsies and histopathology subsequently confirmed that tumor was SCC. The patient then underwent proximal gastrectomy with resection of the diaphragmatic crus. Following surgery, histopathological examination revealed gastric metastasis from primary lung SCC. Key points Gastric metastasis of primary lung carcinoma is one of the rarest phenomena. Gastrointestinal symptoms should raise suspicion of the presence of advanced metastatic disease with poor prognosis.

Abstract While cancer cells gain aggressiveness by mutations, abundant mutations release neoantigens, attracting anti-cancer immune cells. We hypothesized that in breast cancer (BC), where mutation is less common, tumors with high mutation rates demonstrate aggressive phenotypes and attract immune cells simultaneously. High mutation rates were defined as the top 10% of the mutation rate, utilizing TCGA and METABRIC transcriptomic data. Mutation rate did not impact survival although high mutation BCs were associated with aggressive clinical features, such as more frequent in ER-negative tumors (p

Gastric cancer is one of the most common and clinically important diseases worldwide. The traditional Laeuren classification divides gastric cancer into two histopathological subtypes: diffuse and intestinal. Recent cancer genomics research has led to the development of a new classification based on molecular characteristics. The newly defined genomically stable (GS) subtype shares many cases with the histopathologically diffuse type. In this study, we performed genetic profiling of recurrently and significantly mutated genes in diffuse type and GS subtype tumors. We observed significantly different genetic characteristics, although the two subtypes overlapped in many cases. In addition, based on the profiles of the significantly mutated genes, we identified molecular functions and mutational signatures characteristic of each subtype. These results will advance the clinical application of the diffuse type and GS subtype gastric cancer in precision medicine for treating gastric cancer.

Abstract Background There is no comprehensive agreement concerning the overall performance of radical resection for T1b gallbladder cancer (GBC). This research focused on addressing whether T1b GBC may spread loco-regionally and whether radical resection is necessary. Methods A retrospective analysis was conducted of 1032 patients with GBC who underwent surgical resection at our centre and its affiliated institutions between January 1982 and December 2018. A total of 47 patients with T1b GBC, 29 (62%) of whom underwent simple cholecystectomy and 18 (38%) of whom underwent radical resection with regional lymph node dissection, were enrolled in the study. Results GBC was diagnosed pre-operatively in 16 patients (34%), whereas 31 patients (66%) had incidental GBC. There was no blood venous or perineural invasion in any patient on histology evaluation, except for lymphatic vessel invasion in a single patient. There were no metastases in any analysed lymph nodes. The open surgical approach was more prevalent among the 18 patients who underwent radical resection (open in all 18 patients) than among the 29 patients who underwent simple cholecystectomy (open in 21; laparoscopic in 8) (P = 0.017). The cumulative 10- and 20-year overall survival rates were 65 and 25%, respectively. The outcome following simple cholecystectomy (10-year overall survival rate of 66%) was akin to that following radical resection (64%, P = 0.618). The cumulative 10- and 20-year disease-specific survival rates were 93 and 93%, respectively. The outcome following simple cholecystectomy (10-year disease-specific survival rate of 100%) was equivalent to that following radical resection (that of 86%, P = 0.151). While age (> 70 years, hazard ratio 5.285, P = 0.003) and gender (female, hazard ratio 0.272, P = 0.007) had a strong effect on patient overall survival, surgical procedure (simple cholecystectomy vs. radical resection) and surgical approach (open vs. laparoscopic) did not. Conclusions Most T1b GBCs represent local disease. As pre-operative diagnosis, including tumour penetration of T1b GBC, is difficult, the decision of radical resection is justified. Additional radical resection is not required following simple cholecystectomy provided that the penetration depth is restricted towards the muscular layer and that surgical margins are uninvolved.

Abstract Background The cystic duct has been included in the staging classification scheme for gallbladder cancer since the 2010 publication of the AJCC Cancer Staging Manual (7th edition). To our knowledge, only seven other cases of adenocarcinoma arising in the remnant cystic duct following cholecystectomy have been reported in the English-language literature, and none has been reported as primary early-stage T1b remnant cystic duct cancer (CDC). We report, herein, a case of primary adenocarcinoma arising in the remnant cystic duct in a patient with history of laparoscopic cholecystectomy for gallstone disease. Case presentation An 81-year-old female presented with abdominal pain. Her medical history included a laparoscopic cholecystectomy for cholecystolithiasis two years prior. Jaundice was observed; imaging studies suggested that this was caused by choledocholithiasis. Blood chemistry findings showed severe liver dysfunction. Endoscopic retrograde cholangiography revealed haemobilia from the common bile duct with no evidence of choledocholithiasis. A bile sample showed Papanicolaou class IV cytology. As the extent of tumour spread was undetermined by abdominal ultrasonography and endoscopic ultrasonography, peroral cholangioscopy (POCS) was performed, which revealed tiny papillary lesions within the confluence of cystic duct, and fine granular lesions in the centre of bile ducts, signifying early-stage remnant CDC. Extrahepatic bile duct resection with regional lymphadenectomy was done. Histopathological findings revealed a 42-mm tubular adenocarcinoma originating from the remnant cystic duct with the considerable shallow spread across the extrahepatic bile ducts. It invaded the fibromuscular layer, with no lymphovascular or perineural invasion, no lymph node metastasis (13 nodes examined), and uninvolved surgical resection margin (R0 resection), and was staged as pT1bN0M0, Stage I. Conclusions Primary early-stage T1b remnant CDC is an uncommon condition for which early diagnosis is challenging; if intraoperatively recognized, it can complicate surgery. Our experience of this case and an overview of the English literature suggest that POCS is an efficient tool to diagnosis this tumour and assess its spread along the extrahepatic bile ducts.

Abstract Epithelioid glioblastoma is a rare aggressive variant of glioblastoma (GBM) characterized by a dismal prognosis of about 6 months and frequent leptomeningeal dissemination. A recent study has revealed that 50% of epithelioid GBMs harbor three genetic alterations – BRAF V600E mutation, TERT promoter mutations, and homozygous deletions of CDKN2A/2B. Emerging evidence support the effectiveness of targeted therapies for brain tumors with BRAF V600E mutation. Here we describe a dramatic radiographical response to combined therapy with BRAF and MEK inhibitors in a patient with epithelioid GBM harboring BRAF V600E mutation, characterized by thick spinal dissemination. From relapsed tumor procured at autopsy, we established a cell line retaining the BRAF V600E mutation, TERT promoter mutation and CDKN2A/2B loss. Intracranial implantation of these cells into mice resulted in tumors closely resembling the original, characterized by epithelioid tumor cells and dissemination, and invasion into the perivascular spaces. We then confirmed the efficacy of treatment with BRAF and MEK inhibitor both in vitro and in vivo. Epithelioid GBM with BRAF V600E mutation can be considered a good treatment indication for precision medicine, and this patient-derived cell line should be useful for prediction of the tumor response and clarification of its biological characteristics.

Abstract Background Neurofibromatosis type 1 (NF1) is an autosomal dominant disease of the skin and soft tissue. Aneurysms associated with NF1 can occur, but a secondary aneurysm rupture is very rare, with very few cases reported in literature. Case presentation We describe the case of a 67-year-old female with NF1 who underwent endovascular aneurysm repair (EVAR) for an abdominal aortic aneurysm (AAA) rupture. She developed a type Ib endoleak requiring a redo-EVAR. Eighteen days after her primary operation, she was found to have two new left colic artery aneurysms. She required emergency surgery consisting of a left hemicolectomy and transverse colon colostomy. Pathology showed neurofibromatous changes to the peri-vasculature tissue, consistent with her underlying disease. Conclusions Although rare, secondary aneurysms can occur following AAA repair. Patients with soft tissue connective tissue disorders, like NF1, may be at an increased risk for development of these secondary aneurysms. Endovascular repair appears to be a safe approach for NF1 patients with AAA, but endovascular management can be challenging in the setting of NF1. Surgeons should be ready to convert to open surgery if the patient displays persistent signs of bleeding or structural changes related to connective tissue disorders like NF1.

Summary: Background/Objective: Restorative proctocolectomy (RP) may improve quality of life in patients with ulcerative colitis (UC)-associated lower rectal cancer to a greater extent than total proctocolectomy. However, patients with UC-associated cancer often have flat mucosal lesions that make it extremely difficult to endoscopically delineate the tumor margins. Therefore, there is a potential risk of residual tumor and local recurrence after RP in patients with UC-associated lower rectal cancer. The aim of this study was to assess the feasibility of RP in patients with UC-associated cancer of the lower rectum. Methods: We retrospectively identified nine patients who had undergone RP for UC-associated lower rectal cancer at the Niigata University Medical and Dental Hospital between January 2000 and December 2016. The incidence of flat mucosal cancer, distal margin status, and oncologic outcomes were evaluated in the nine patients. Results: Eight (89%) of the nine patients had flat mucosal cancer in the lower rectum. The median length of the distal margin was 22 mm (range 0–55 mm). No patient developed local or distant recurrence during follow-up. One patient had a positive distal margin. This patient underwent annual pouchoscopy, but had no local recurrence and died of pancreatic cancer 81 months after RP. The remaining eight patients were alive at the final observation. Five-year and 10-year overall survival rates in the nine patients were 100% and 66.7%, respectively. Conclusion: Patients with UC-associated lower rectal cancer often have lesions of the flat mucosal type. However, RP is feasible and not necessarily contraindicated in such patients. Keywords: inflammatory bowel disease, rectal cancer, restorative proctocolectomy, ulcerative colitis, ulcerative colitis-associated cancer

Objectives: A number of patients have developed liver failure after the Kasai operation for biliary atresia (BA), even after long-term postoperative course. We report our experience regarding four cases of biliary atresia required and treated with living donor liver transplantation (LDLT) during adulthood. Methods: All four patients underwent Kasai operation for BA from 1974 to 1983 and had been followed-up for more than 30 years in our institute. Then, they developed liver failure and treated with LDLT. These four patients’ records were reviewed retrospectively. All data are described using the median value. Results: Three female and one male were included. Kasai operation was performed at the age of 61 days. The type of biliary obstruction was type III-b1-ν in all. The survival period of the native liver was 440 months. The age at LDLT was 37 years. The reasons of deterioration of native liver were recurrent cholangitis in two and pregnancy and delivery in other two. The age of living donor was 40 years. Right liver grafts were used in all. Percentage of the real graft volume per standard liver volume was 47%. All patients were alive and overall graft survival rate was 100% at a follow-up period of 65 months after LDLT. Conclusion: Even after more than 30 year-survival with native liver after Kasai operation, liver failure may be caused by recurrent cholangitis or pregnancy and delivery. LDLT may be effective treatment for those adult patients if an adequate living donor is available.

Abstract Lymphatic metastasis is known to contribute to worse prognosis of biliary tract cancer (BTC). Recently, sphingosine-1-phosphate (S1P), a bioactive lipid mediator generated by sphingosine kinase 1 (SPHK1), has been shown to play an important role in lymphangiogenesis and lymph node metastasis in several types of cancer. However, the role of the lipid mediator in BTC has never been examined. Here we found that S1P is elevated in BTC with the activation of ceramide-synthetic pathways, suggesting that BTC utilizes SPHK1 to promote lymphatic metastasis. We found that S1P, sphingosine and ceramide precursors such as monohexosyl-ceramide and sphingomyelin, but not ceramide, were significantly increased in BTC compared to normal biliary tract tissue using LC-ESI-MS/MS. Utilizing The Cancer Genome Atlas cohort, we demonstrated that S1P in BTC is generated via de novo pathway and exported via ABCC1. Further, we found that SPHK1 expression positively correlated with factors related to lymphatic metastasis in BTC. Finally, immunohistochemical examination revealed that gallbladder cancer with lymph node metastasis had significantly higher expression of phospho-SPHK1 than that without. Taken together, our data suggest that S1P generated in BTC contributes to lymphatic metastasis.

Abstract Background Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn’s disease (CD), is a chronic, idiopathic, repeated inflammatory disease. Colorectal cancer (CRC) that develops in patients with IBD is known as colitis-associated colorectal cancer (CAC), but the underlying carcinogenic mechanism remains unclear. Genomic analysis of sporadic CRC has been well described based on next-generation sequencing (NGS) data. Using NGS, we compared all exons of 415 cancer-associated genes in patients in Japan and the USA who had CRC and found similar genomic alteration patterns among the two populations. However, genomic analysis of CAC has not been thoroughly investigated. Main body The molecular pathogenesis of CAC shares many features with sporadic CRC, but there are distinct variations in the time and frequency of some alterations. Gene alterations in CAC are gradually being elucidated using genomic sequencing analyses. Some studies have shown that gene alteration patterns differ between UC and CD. The carcinogenesis of CAC depends on unique environmental, genetic, and immunological factors. Conclusions In this review, we have discussed the differences in genomic alterations between sporadic CRC and CAC. NGS in patients with IBD has the potential to detect early CAC and to suggest therapeutic targets.

Purpose Small bowel obstruction (SBO) remains a common complication after pelvic or abdominal surgery. However, the risk factors for SBO in ulcerative colitis (UC) surgery are not well known. The aim of the present study was to clarify the risk factors associated with SBO after ileal pouch-anal anastomosis (IPAA) with a loop ileostomy for patients with UC. Methods The medical records of 96 patients who underwent IPAA for UC between 1999 and 2011 were reviewed. SBO was confirmed based on the presence of clinical symptoms and radiographic findings. The patients were divided into 2 groups: the SBO group and the non-SBO group. We also analyzed the relationship between SBO and computed tomography (CT) scan image parameters. Results The study included 49 male and 47 female patients. The median age was 35.5 years (range, 14–72 years). We performed a 2- or 3-stage procedure as a total proctocolectomy and IPAA for patients with UC. SBO in the pretakedown of the loop ileostomy after IPAA occurred in 22 patients (22.9%). Moreover, surgical intervention for SBO was required for 11 patients. In brief, closure of the loop ileostomy was performed earlier than expected. A multivariate logistic regression analysis revealed that the 2-stage procedure (odds ratio, 2.850; 95% confidence interval, 1.009–8.044; P = 0.048) was a significant independent risk factor associated with SBO. CT scan image parameters were not significant risk factors of SBO. Conclusion The present study suggests that a 2-stage procedure is a significant risk factor associated with SBO after IPAA in patients with UC.

Abstract Background Intertumoral heterogeneity represents a significant hurdle to identifying optimized targeted therapies in gastric cancer (GC). To realize precision medicine for GC patients, an actionable gene alteration-based molecular classification that directly associates GCs with targeted therapies is needed. Methods A total of 207 Japanese patients with GC were included in this study. Formalin-fixed, paraffin-embedded (FFPE) tumor tissues were obtained from surgical or biopsy specimens and were subjected to DNA extraction. We generated comprehensive genomic profiling data using a 435-gene panel including 69 actionable genes paired with US Food and Drug Administration-approved targeted therapies, and the evaluation of Epstein-Barr virus (EBV) infection and microsatellite instability (MSI) status. Results Comprehensive genomic sequencing detected at least one alteration of 435 cancer-related genes in 194 GCs (93.7%) and of 69 actionable genes in 141 GCs (68.1%). We classified the 207 GCs into four The Cancer Genome Atlas (TCGA) subtypes using the genomic profiling data; EBV (N = 9), MSI (N = 17), chromosomal instability (N = 119), and genomically stable subtype (N = 62). Actionable gene alterations were not specific and were widely observed throughout all TCGA subtypes. To discover a novel classification which more precisely selects candidates for targeted therapies, 207 GCs were classified using hypermutated phenotype and the mutation profile of 69 actionable genes. We identified a hypermutated group (N = 32), while the others (N = 175) were sub-divided into six clusters including five with actionable gene alterations: ERBB2 (N = 25), CDKN2A, and CDKN2B (N = 10), KRAS (N = 10), BRCA2 (N = 9), and ATM cluster (N = 12). The clinical utility of this classification was demonstrated by a case of unresectable GC with a remarkable response to anti-HER2 therapy in the ERBB2 cluster. Conclusions This actionable gene-based classification creates a framework for further studies for realizing precision medicine in GC.

Abstract Background Laparoscopic surgery for patients with portal hypertension is considered to be contraindicated because of the high risk of massive intraoperative hemorrhaging. However, recent reports have shown hand-assisted laparoscopic surgery for devascularization and splenectomy to be a safe and effective method of treating esophagogastric varices with portal hypertension. The aim of this study is to evaluate the efficacy of hand-assisted laparoscopic devascularization and splenectomy (HALS Hassab’s procedure) for the treatment of esophagogastric varices with portal hypertension. Case presentation From 2009 to 2016, seven patients with esophagogastric varices with portal hypertension were treated with hand-assisted laparoscopic devascularization and splenectomy in our institute. Four men and three women with a median age of 61 years (range 35–71) were enrolled in this series. We retrospectively reviewed the medical records for the perioperative variables, postoperative mortality and morbidity, and postoperative outcomes of esophagogastric varices. The median operative time was 455 (range 310–671) min. The median intraoperative blood loss was 695 (range 15–2395) ml. The median weight of removed spleen was 507 (range 242–1835) g. The conversion rate to open surgery was 0%. The median postoperative hospital stay was 21 (range 13–81) days. During a median 21 (range 3–43) months of follow-up, the mortality rate was 0%. Four postoperative complications (massive ascites, enteritis, intra-abdominal abscess, and intestinal ulcer) were observed in two patients. Those complications were treated successfully without re-operation. Esophagogastric varices in all patients disappeared or improved. Bleeding from esophagogastric varices was not observed during the follow-up period. Conclusion Although our data are preliminary, hand-assisted laparoscopic devascularization and splenectomy proved an effective procedure for treating esophagogastric varices in patients with portal hypertension.

Abstract Background Benign esophageal tumors are uncommon, comprising approximately 2% of esophageal tumors. Esophageal schwannomas constitute an even rarer entity, with few cases reported in the literature. Case presentation We present a 66-year-old male who was referred for dysphagia. A computed tomography scan showed a well-demarcated, enhancing, and homogenous esophageal tumor measuring 50 mm. The tumor was hypermetabolic on positron emission tomography, and an endoscopic ultrasound-guided fine needle aspiration demonstrated the presence of benign spindle cells. We performed an uncomplicated, simple, tumor enucleation through a cervical approach. Histology revealed spindle-shaped cells in a fasciculated, disarrayed pattern. Immunohistochemistry demonstrated positive staining for S-100 protein and negative staining for KIT, CD34, desmin, and α-smooth muscle actin. These findings were consistent with a benign esophageal schwannoma. Conclusions We report our experience with esophageal schwannoma, a rare but benign diagnosis of the esophagus.

Bile acids (BA) are synthesized from cholesterol in the liver. They are essential for promotion of the absorption of lipids, cholesterol, and lipid-soluble vitamins from the intestines. BAs are hormones that regulate nutrient metabolism by activating nuclear receptors (farnesoid X receptor (FXR), pregnane X receptor, vitamin D) and G protein-coupled receptors (e.g., TGR5, sphingosine-1-phosphate receptor 2 (S1PR2)) in the liver and intestines. In the liver, S1PR2 activation by conjugated BAs activates the extracellular signal-regulated kinase 1/2 and AKT signaling pathways, and nuclear sphingosine kinase 2. The latter produces sphingosine-1-phosphate (S1P), an inhibitor of histone deacetylases 1/2, which allows for the differential up-regulation of expression of genes involved in the metabolism of sterols and lipids. We discuss here the emerging concepts of the interactions of BAs, FXR, insulin, S1P signaling and nutrient metabolism. Keywords: Sphingosine-1-phosphate, Sphingosine kinase 2, Sphingosine-1-phosphate receptor 2, Fatty liver, Epigenetics

Abstract Background A gastric adenosquamous carcinoma (ASC) that produces granulocyte-colony stimulating factor (G-CSF) is an uncommon malignancy with a poor prognosis. Due to the rarity of this lesion, a standard treatment for the disease has not been established. Case presentation We describe a case of a 66-year-old male with a G-CSF-producing gastric ASC who presented with severe anemia and leukocytosis. A radical resection was performed, followed by a course of adjuvant chemotherapy. Histopathologic examination revealed that the tumor consisted of areas of both squamous cell carcinoma and adenocarcinoma. Immunohistochemical staining with an anti-G-CSF antibody was also positive. He was started on adjuvant capecitabine and oxaliplatin (CapeOX) 6 weeks after surgery. The patient stopped treatment after 3 months due to his own preference. Eight months following surgery, the patient was found to have diffuse lymph node, liver, and peritoneal metastases. Conclusions G-CSF-producing gastric ASC is a rare and aggressive tumor. Because patients are usually diagnosed at an advanced stage, multidisciplinary evaluation and innovative treatments are needed. The rarity of this disease, with its aggressive features, poses a significant challenge in its treatment. In this brief case report, we summarize the management and outcomes of G-CSF-producing gastric ASC.

Based on research carried out over the last decade, it has become increasingly evident that bile acids act not only as detergents, but also as important signaling molecules that exert various biological effects via activation of specific nuclear receptors and cell signaling pathways. Bile acids also regulate the expression of numerous genes encoding enzymes and proteins involved in the synthesis and metabolism of bile acids, glucose, fatty acids, and lipoproteins, as well as energy metabolism. Receptors activated by bile acids include, farnesoid X receptor α, pregnane X receptor, vitamin D receptor, and G protein-coupled receptors, TGR5, muscarinic receptor 2, and sphingosine-1-phosphate receptor (S1PR)2. The ligand of S1PR2, sphingosine-1-phosphate (S1P), is a bioactive lipid mediator that regulates various physiological and pathophysiological cellular processes. We have recently reported that conjugated bile acids, via S1PR2, activate and upregulate nuclear sphingosine kinase 2, increase nuclear S1P, and induce genes encoding enzymes and transporters involved in lipid and sterol metabolism in the liver. Here, we discuss the role of bile acids and S1P signaling in the regulation of hepatic lipid metabolism and in hepatobiliary diseases.

Dysregulation of p62 has been implicated in tumorigenesis. Here, the authors show that p62 promotes hepatocellular carcinoma by reprogramming glucose and glutamine metabolism through Nrf2 and present a novel compound that can inhibit p62 action thus sensitizing cancer cells to chemotherapy.

E2F transcription factors play critical roles in the cell cycle. Therefore, their activity is expected to reflect tumor aggressiveness and responsiveness to therapy. We scored 3905 tumors of nine breast cancer cohorts for this activity based on their gene expression for the Hallmark E2F targets gene set. As expected, tumors with a high score had an increased expression of cell proliferation-related genes. A high score was significantly associated with shorter patient survival, greater MKI67 expression, histological grade, stage, and genomic aberrations. Furthermore, metastatic tumors had higher E2F scores than the primary tumors from which they arose. Although tumors with a high score had greater infiltration by both pro- and anti-cancerous immune cells, they had an increased expression of immune checkpoint genes. Estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative cancer with a high E2F score achieved a significantly higher pathological complete response (pCR) rate to neoadjuvant chemotherapy. The E2F score was significantly associated with the expression of cyclin-dependent kinase (CDK)-related genes and strongly correlated with sensitivity to CDK inhibition in cell lines. In conclusion, the E2F score is a marker of breast cancer aggressiveness and predicts the responsiveness of ER-positive/HER2-negative patients to neoadjuvant chemotherapy and possibly to CDK and immune checkpoint inhibitors.

Elucidating the interaction between cancer and non-cancer cells, such as blood vessels, immune cells, and other stromal cells, in the tumor microenvironment is imperative in understanding the mechanisms underlying cancer progression and metastasis, which is expected to lead to the development of new therapeutics. Sphingosine-1-phosphate is a bioactive lipid mediator that promotes cell survival, proliferation, migration, angiogenesis/lymphangiogenesis, and immune responsiveness, which are all factors involved in cancer progression. Sphingosine-1-phosphate is generated inside cancer cells by sphingosine kinases and then exported into the tumor microenvironment. Although sphingosine-1-phosphate is anticipated to play an important role in the tumor microenvironment and cancer progression, determining sphingosine-1-phosphate levels in the tumor microenvironment has been difficult due to a lack of established methods. We have recently developed a method to measure sphingosine-1-phosphate levels in the interstitial fluid that bathes cancer cells in the tumor microenvironment, and reported that high levels of sphingosine-1-phosphate exist in the tumor interstitial fluid. Importantly, sphingosine-1-phosphate can be secreted from cancer cells and non-cancer components such as immune cells and vascular/lymphatic endothelial cells in the tumor microenvironment. Furthermore, sphingosine-1-phosphate affects both cancer and non-cancer cells in the tumor microenvironment promoting cancer progression. Here, we review the roles of sphingosine-1-phosphate in the interaction between cancer and non-cancer cells in tumor microenvironment, and discuss future possibilities for targeted therapies against sphingosine-1-phosphate signaling for cancer patients.

Breast cancer metastasizes to lymph nodes or other organs, which determine the prognosis of patients. It is difficult to cure the breast cancer patients with distant metastasis due to resistance to drug therapies. Elucidating the underlying mechanisms of breast cancer metastasis and drug resistance is expected to provide new therapeutic targets. Sphingosine-1-phosphate (S1P) is a pleiotropic, bioactive lipid mediator that regulates many cellular functions, including proliferation, migration, survival, angiogenesis/lymphangiogenesis, and immune responses. S1P is formed in cells by sphingosine kinases and released from them, which acts in an autocrine, paracrine, and/or endocrine manner. S1P in extracellular space, such as interstitial fluid, interacts with components in the tumor microenvironment, which may be important for metastasis. Importantly, recent translational research has demonstrated an association between S1P levels in breast cancer patients and clinical outcomes, highlighting the clinical importance of S1P in breast cancer. We suggest that S1P is one of the key molecules to overcome the resistance to the drug therapies, such as hormonal therapy, anti-HER2 therapy, or chemotherapy, all of which are crucial aspects of a breast cancer treatment.

The main function of the lymphatic system is to control and maintain fluid homeostasis, lipid transport, and immune cell trafficking. In recent years, the pathological roles of lymphangiogenesis, the generation of new lymphatic vessels from preexisting ones, in inflammatory diseases and cancer progression are beginning to be elucidated. Sphingosine-1-phosphate (S1P), a bioactive lipid, mediates multiple cellular events, such as cell proliferation, differentiation, and trafficking, and is now known as an important mediator of inflammation and cancer. In this review, we will discuss recent findings showing the emerging role of S1P in lymphangiogenesis, in inflammation, and in cancer.

Background: Sphingosine-1-phosphate (S1P) is a pleiotropic bioactive lipid mediator that regulates many physiological and pathological processes. It has been suggested that S1P gradient with high concentrations in the blood and lymphatic fluid and low concentrations in the peripheral tissue plays important roles in immune cell trafficking and potentially cancer progression. However, only a few reports have assessed S1P levels in the lymphatic fluid due to lack of an established easy-to-use method. Here, we report a simple technique for collection of lymphatic fluid to determine S1P. Materials and methods: Lymphatic fluid was collected directly with a catheter needle (classical method) or was absorbed onto filter paper after incision of cisterna chyli (new method) in murine models. Blood, lymphatic fluid and mesenteric lymph nodes were corrected from wild type and sphingosine kinase 2 (SphK2) knockout mice to determine S1P levels by mass spectrometry. Results: The volume of lymphatic fluid collected by the new method was at least three times greater than those collected by the classical method. S1P concentrations in lymphatic fluid are lower than in blood and higher than in lymph nodes. Interestingly, S1P levels in lymphatic fluid from SphK2 knockout mice were significantly higher than those in wild type, suggesting an important role of SphK2 and/or SphK1 to regulate S1P levels in lymphatic fluid. Conclusions: In agreement with the previous theory, our results confirm “S1P gradient” among blood, lymphatic fluid and peripheral lymphatic tissues. Convenient methods for collection and measurement of sphingolipids in lymphatic fluid are expected to provide new insights on functions of sphingolipids.